Bit dark, If I could guess I would say that someone told you to underexpose your d40 by 2/3's to get a proper exposure. If I'm right.. That piece of advice is good for a few applications but for what looks like a gloomier day that won't be necessary. These could use a boost in exposure for sure.

I haven't heard about that underexposure trick. But it was my first day out it was dark and cloudy. So I probably had them wrongly exposed.

going to check out what I can do for these in photoshop.

cheers

EDIT: just checked the images out, and it appears that they got desaturated a little bit in the process from my computer to the photo forum. Which is unfortunate, the top portraite is a lot warmer and the last 2 don't look quite as dark. I did increase the exposure in the last 2 though. Thanks!